1. Field of the Invention
The present general inventive concept relates to a disk spacer of a hard disk drive (HDD), and more particularly, to a disk spacer located between a pair of adjacent disks to maintain a constant gap between the disks, when a plurality of disks are mounted on a spindle motor, and an HDD having the disk spacer.
2. Description of the Related Art
An HDD is a supplementary memory device used in personal computers (PCs), MP3 players, mobile phones, etc. which uses a magnetic head to read data from and write data on a disk. The disk is mounted on and rotated by a spindle motor, and the magnetic head floats over the rotating disk.
HDDs using 3.5 inch or 2.5 inch-diameter disks can be given various storage capacities by installing either one or two disks on the same spindle motor. Thus, an HDD having only one disk has the same height as an HDD having two disks. However, small HDDs using disks of 1.8-inch diameter or less use different spindle motors to install different numbers of disks.
FIGS. 1 and 2 are cross-sectional diagrams illustrating conventional HDDs having 1.8-inch diameter disks. FIG. 1 illustrates an HDD 10 having two disks, and FIG. 2 illustrates an HDD 50 having only one disk.
Referring to FIG. 1, the HDD 10 includes a base member 11, a cover member 13 assembled with the base member 11, a spindle motor 20 mounted on the base member 11, and first and second disks 15 and 17 mounted on the spindle motor 20. The spindle motor 20 includes a shaft 21, on which are mounted a stator 23 and a rotator 25. The rotator 25 may also be called a hub. The rotator 25 includes a cylindrical circumference part 27 and a flange 26 projecting outwards from below the cylindrical circumference part 27.
The first and second disks 15 and 17 are put onto the cylindrical circumference part 27, and the first disk 15 is supported by the flange 26. A ring-shaped spacer 19 is located between the first and second disks 15 and 17 to separate them. The pair of disks 15 and 17 are fixed to the rotator 25 by a disk clamp 30 pressed by a clamping screw 35 screwed into the shaft 21.
Referring to FIG. 2, the HDD 50 includes a base member 51, a cover member 53 assembled with the base member 51, a spindle motor 60 mounted on the base member 51, and a disk 55 mounted on the spindle motor 60. The spindle motor 60 includes a shaft 61, on which are mounted a stator 63 and a rotator 65. The rotator 65 may also be called a hub. The rotator 65 includes a cylindrical circumference part 67 and a flange 66 projecting outwards from below the cylindrical circumference part 67.
The disk 55 is put onto the cylindrical circumference part 67 and supported by the flange 66. The disk 55 is fixed to the rotator 65 by a disk clamp 70 pressed by a clamping screw 75 screwed into the shaft 61.
The cylindrical circumference part 67 of FIG. 2 is shorter than the cylindrical circumference part 27 of FIG. 1, allowing a height H2 of the HDD 50 using only one disk to be less than a height H1 of the HDD 10 using two disks. However, since two types of spindle motors (20 of FIG. 1 and 60 of FIG. 2) must be manufactured for disks of the same diameter, manufacturing costs are increased by a lack of common parts.